1. Technical Field
The present invention relates to a printing apparatus and a printing method.
2. Related Art
Among various ink jet printers, there is a type in which paper of large sizes such as A2 or larger is used. In the ink jet printer for large size paper, a so-called roll paper is used in many cases in addition to cut paper. In the following description, the roll paper, which is paper in a rolled state, is referred to as a “roll member” and a portion pulled out from the roll member is referred to as “paper”.
Pulling out of the paper from the roll member is achieved by rotating a transporting roller by a paper feed motor (PF motor). The PF motor is controlled and driven by a PID control.
A printer in which the roll member as described above is used is described in JP-A-2007-290866. Also, a printer that performs the PID control is described in JP-A-2006-240212, JP-A-2003-79177, and JP-A-2003-48351.
Since the transporting roller is generally set apart from the roll member mounted on a printer body by a certain distance in the direction in which the paper is supplied, the paper pulled out from the roll member may slack between the roll member and the transporting roller.
For example, when a printing job is started, a user performs an operation to pull out a paper from the roll member mounted on the printer body and set the same to a paper feed mechanism including the PF motor and the transporting roller. At this time, the paper might slack between the roll member and the paper feed mechanism. After having set the paper in the paper feed mechanism, there is a case where the paper is fed backward (rewound) for accessing a leading edge. In such a case as well, the paper may slack.
When a printing process is performed on the slacked paper, a printed image is distorted, whereby the image quality is deteriorated. Then, normally, the user checks such slackness as needed and, when it is determined that the paper is slacked, the user, for example, rotates the roll member with hand and winds the slacked portion of the paper.
In this manner, in the printer using the roll member, there is a problem such that the user needs to eliminate the slackness of the paper manually, which is a time-consuming job. When the slackness is overlooked, or when the slackness is not sufficiently cancelled, the printed image might be distorted.